Type I Diabetes.

Treatment with insulin within 3 months prior to screening

History of diabetic ketoacidosis or lactic acidosis

Allergy or sensitivity to metformin or similar drugs or any medical conditions which prohibit metformin use

Excessive blood donation 56 days before the start of the study

Urinary tract or bladder infections within four weeks of study start

Alcohol abuse or illicit drug use within 12 months of study start

Receiving other investigational drugs or participating in other research trials within 30 of the study start

Use of prescription or non-prescription drugs, including vitamins, herbal and dietary supplements with 7-14 days of study start

Live alone without regular, daily interactions with someone who can be an emergency contact

A Study To Assess The Safety And Tolerability Of GSK189075 When Given With A Total Daily Dose Of >/ 2000mg of Metformin